Figure 2.

The RGG box motif and CTD together are essential and sufficient to inhibit translation.A, schematic of recombinant WT and mutant NT-hFMRP. Mutated/truncated domains are highlighted in red. B, Coomassie stain of recombinant proteins. C–I, in vitro translation of nLuc mRNA with a titration of recombinant WT and mutant NT-hFMRP isoforms. IC₅₀ values were determined for the His6-MBP tag (negative control; 633.50 ± infinity μM) (C), WT NT-hFMRP (D), I304N KH2 domain patient-derived mutant NT-hFMRP (E), ΔRGG + CTD mutant NT-hFMRP (25.72 ± infinity μM) (F), the RGG box motif + CTD fusion (G), the RGG box motif alone (H), and the CTD alone (5.75 × 10³³ ± infinity μM) (I). n = 3 biological replicates. A nonlinear regression was used to calculate the IC₅₀ and is shown as the line with the 95% confidence interval (CI) included as a watermark. The IC₅₀ is reported ± 95% CI. CTD, C-terminal domain.